Open Access research with a European policy impact...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by Strathclyde researchers, including by researchers from the European Policies Research Centre (EPRC).

EPRC is a leading institute in Europe for comparative research on public policy, with a particular focus on regional development policies. Spanning 30 European countries, EPRC research programmes have a strong emphasis on applied research and knowledge exchange, including the provision of policy advice to EU institutions and national and sub-national government authorities throughout Europe.

Abstract

The influence of the personal computer processing mode on the generation of line current harmonics has been investigated using a university library building containing over 370 PCs. The harmonics were monitored from the building switchboard using purpose-designed hardware. The PCs were set to execute four types of processing mode: idle, numerical processing, floppy, and hard disk accesses. The results recorded were indicative of harmonics caused by the PC box only, and secondary effects of harmonic production caused by distorted supply voltages were avoided. The results show that hard disk accesses cause the highest level of harmonic production affecting the 3rd and 5th components. Harmonic attenuation was very apparent when comparing the results between a single PC and 124 PCs connected to the same supply phase. However, attenuation and diversity effects due to changes in loading level on the PC power supply were not as predicted, showing an increase in harmonic generation with line current RMS level.

Item type:

Article

ID code:

3576

Keywords:

computer power supplies, microcomputers, power supply, power system harmonics, power systems, Electrical engineering. Electronics Nuclear engineering, Energy Engineering and Power Technology, Electrical and Electronic Engineering